Abstract In a recently published video by GIBA Caravan-Technik GmbH various concerns regarding the use of LiFePO4 (LFP) battery cells as starter batteries in motorhomes and camping vehicles were addressed...
Although these concerns may seem worrying at first glance, we at LITEWERKS engineering would like to explain why our LITE BLOX not only overcomes these challenges, but rather offers significant advantages in terms of reliability & safety compared to the classic car starter battery. Battery management system (BMS) Our specially developed, intelligent BMS is designed to sustainably prevent potential malfunctions through redundancies and plausibility checks and also complies with common automotive standards.
The shutdown scenarios are selected in such a way that intervention is not necessary under normal operating conditions.
Furthermore, we have implemented a technology-leading "soft close" function that enables us to offer users an early warning system when starting the vehicle in the event of a malfunction in the vehicle peripherals, without the vehicle shutting down while driving.
With this in mind, our BMS does NOT switch at the 14.4 volts mentioned in the video, but rather uses numerous parameters before a - safety-relevant - hard shutdown occurs - e.g. in the event of a short circuit or LIMA regulator damage (both scenarios under which a classic car starter battery can also thermally run down or fail in a safety-relevant manner).
The premium LFP battery cells used in our LITE BLOX also have a comparatively low internal resistance, which effectively means that voltage fluctuations (up to 15.2V) are better compensated and high recuperation currents (up to 200A) on modern EURO 6c vehicle alternators are accompanied by less wear than with conventional lead-acid-based car batteries (GEL, AGM...).
It is not for nothing that the ADAC (German Automobile Association) lists the car starter battery as one of the top 3 sources of failure in current surveys and certifies an average service life of <4 years... Battery cells (LiFePO4 / lithium iron phosphate) Commercially available lithium-based battery cells are subject to strong fluctuations in manufacturing quality, service life and load capacity.
As an ISO:9001 certified company, we only use pre-sorted A-grade cells from reputable manufacturers in our LITE BLOX and can also trace our supply chains - in contrast to relevant "market companions" who market goods from China with new stickers in this country.
We would also like to point out that the need for a heating mat at low temperatures mentioned in the video is only relevant for storage or on-board batteries.
For LFP starter batteries, this is not the case due to the specific technology. low temperatures A frequently cited, common reservation is the sensitivity of LFP batteries to temperature changes and voltage fluctuations.
When using sufficiently dimensioned premium LFP cells in conjunction with a BMS designed for automotive applications (-20 to +80C), active heating is actually counter-productive, as the battery cells are no longer subjected to a homogeneous thermal load. As "proof of concept" from >10 years of field use with LITE BLOX, our SMART series has performed reliably in the large EXTREME TEST with rally legend Armin Schwarz at temperatures below -20°C sets, without any measurable or lasting change in the cell chemistry. Safety concerns It should be emphasised in advance that malfunctions in connection with vehicle components can never be completely ruled out - however, well thought-out product design and constant quality control minimise the risk to a minimum.
Lead-acid-based car starter batteries - which are charged with >30V due to failure of the LIMA regulator, for example - also react and form gases, which can lead to decomposition.
Furthermore, the test carried out in the video, in which the terminal of a lead-acid battery is disconnected while stationary, is not directly comparable with the behaviour while driving, which underlines the complexity and the need for a sound understanding of battery technology and the design of suitable products in the state of the art. Conclusion While concerns about the use of such technologies in low-cost products are justified, as a German development company, we ensure that we are able to meet these challenges sustainably through advanced technology and telemetry data from >5000 units in field use over the past 10 years.
Best regards from Lake Constance & we are always available to answer your questions about LFP starter batteries Frederic & the LITEWERKS engineering team
